Question: $ { \left[\begin{array}{rrr}{2} & {4} & {2} \\ {-2} & {-1} & {-2}\end{array}\right]+\left[\begin{array}{rrr}{-1} & {1} & {4} \\ {1} & {-1} & {-1}\end{array}\right] = {?} } $
To find the sum of two matrices, add the corresponding items between each matrix. ${\left[\begin{array}{rrr}{2}+{-1} & {4}+{1} & {2}+{4} \\ {-2}+{1} & {-1}+{-1} & {-2}+{-1}\end{array}\right]}$ Now, simplify: ${\left[\begin{array}{rrr}{1} & {5} & {6} \\ {-1} & {-2} & {-3}\end{array}\right]}$